Electric connection device



March 2l, 1950 i. KORN 2,501,569

. ELECTRIC CONNECTION 'DEVICE Filed'April 23, 1948 2 Sheets-Sheet 2 porting iframework, casing,

Patented Mar. 2l, 1950 'UNITE-D STATES PATENT GFFICE ELECTRIC CGNNECTION 'DEVICE IsidoreKorn, Newark, N. J.

Application April 23, 1948, Serial No. 22,802

1-Claim.

This :invention :relates to electric switches, re-

ceptacles, vland 'similar .connection devices for electric *wiring installations.

Certain types lof conventional devices vof this xcharacter, `including "those intended 'for heavy lduty yindustrial wiring '-installations, ,as well .as

those for domesticisystems, `comprise switch, outlet, or .other electrical :connection :units :mounted Ain supporting .framework yor enclosing :casings or boxes ifinto which lead :power .supply and .power delivery conductors, suchras cables .or conduits.

.Electrical connection of .-such `units with Vthe electrical conductors fis :made within the supporting Aframework l or enclosing ..casings -or "boxes, Ordi- .narily, wheniit.is .desired to remove ,the connection unit ytherefrom -for repair or replacement, Aor merely for inspection, theelectrical power `leads must 'be disconnected :and fthen reconnected Vat :no ,little difliculty and inconvenience.

Pursuant to the fpresent invention, the supor .box is so con- ;structed that the connection xu-nit per .se may Abe quickly, easily .and :safely removed :and .-replaced, :breaking and :re-making `electrical connection with the power conductors,-withoutfeven the neicessity .ofshutting oi the electric power :flowing through the system.

Accordingly, itis van :object yof pthe invention ato provide an electric connection .device 'wherein .the connection unit may be removed from the .support wherein electrical .connection :is made, e. g. framework, casing, rbox, ibase, or 'the like, for inspection, repair, or replacement, and 'where- 'in that or a substitute `unit vmay be `replaced quickly, easily,-and'safely without shutting offthe Fig. 3 is a vertical `section taken on lthe line .'Fig. i4 is :a view similar to that .of Fig. '3 but llustrating how .the .switch `unit .may be with- .drawn fromrand replaced :within .the .switch box;

Fig. .5 sis .a firont .elevation `of the device as it appears vwith switch box cover and switch unit removed;

Referring vnow to v.the drawings:

The form of the invention illustrated in Figs. .l through 5 is an industrial type, :comprising :a switch box or :casing fill, made up of a deep .box body 10a and :a relatively shallow .close-fitting cover 10b. This switch box is of conventional construction, usually being fabricated of sheet steel and provided with 1.theicustomary weakened knock-out .areas in the side walls of the box lbody for'the introduction of electric :power cables or conduits .at 4optional locations. While the vcomponent parts ofesuch'switch .box are, as ordinarily fmade,.sheet steel stampings bent to shape where necessary, they .may be lformed `of other materials, for example of one of the `wellknown plastics, such as Bakelite, in amanner suitable to the Aparticular material employed. In the illus- 7trated instance end pieces iUc, -l'0c are Welded to the inner upper margins of the end Walls of the 'box body Illa, so `rtheyextend upwardly 'be- -yond -said Aend lwalls and rprovide a neck for the close-fitting accommodation of the cover A10b. Centrally vthereof vthey have Ainwardly projecting ears H, H, Which serve "to receive and support theswitc'h unit.

'The switch unit .is for the most part conventional in construction, and may be of any desired type consistent .with those particular structural features necessary to effect the purposes of the invention, which .features `are detailed here'below in association .withthe correlative fea tures of the cooperating .power-connection assembly.

The various parts of vthe switch unit should be so .integrated ,with oneanother that the combination formsan .assembly independent of the other .portions of lthedevce .and separable .therefrom asa-single .entity. ,'It isfprovided withelectric terminals for close irictional contact -wth corresponding =e1ectric-terniinals .of :the powerconnection .,assembly. from whence :comes :the

electric power flowing to the switch contacts and through said contacts when the switch is closed.

The power-connection assembly is anchored Within the box body to the base thereof, and, when the switch box is installed. ready for use, is in constant electrical connection with the power supply. That connection need never be broken, nor need the electric power supply be shut oi when removing or replacing the switch unit, because the electrical connection between switch unit and power-connection assembly is broken automatically and at a location remote from those parts of the switch unit subject to handling during 'the removing or replacing process.

In the illustrated embodiment, the power-connection assembly is disposed at the bottom or base of the box body Illa, which lies opposite. the opening I2 leading thereinto, and is adapted to be normally closed by the removable cover Ib, Fig. 1. It comprises an insulating base plate I3 anchored to the bottom of the box body, as, for instance, by means of the rivets Ill. Such base plate may be of any rigid insulating material, for instance hard rubber or a suitable plastic, and forms a bed for the desired number of electrical terminal strips I5, here shown as three at each of the opposite ends of the plate, see especially Fig. 5. An insulating top plate It, similar in nature to the base plate I3 but shorter so as to leave end portions of the electrical terminal strips I5 exposed, is superimposed upon the base plate I3 and upon portions of the said terminal strips. Such terminal strips are preferably fastened to the underside of the top plate i5 by means of electrically conductive funnel-shaped grommets I'I, which serve as plug--in sockets, and also by means of screws I8. The top plate It is secured to the bottom plate I3 by means of screws I9, thereby providing a unitary power connection assembly which is secured within the box body lUa in predetermined and unchanging position. Binding-post terminals 2B, disposed in the uncovered ends of the respective electrical terminal strips I5, stand ready for electrical connecltion with the conductors of any electric power supply cable or conduit and corresponding power delivery cable or conduit which may be intrcduced through the respective access passages formed by breaking out the conventional weake ened disc or knock-out portions 2| at either end of the casing body.

The switch unit, designated generally 22, is die-- signed to provide, when closed, an electrical bridge between those electrical terminal strips I5 at one end of the casing and the respectively corresponding terminal strips I5 at the opposite end of the casing, thereby closing the circuit between power supply and power delivery. Accordingly, it possesses opposite sets of stationary electrical contacts 23, and movable electrical conductors 24 capable or establishing electrical connection between corresponding contacts of the said sets of stationary contacts when the switch`= lever or toggle 25 is snappedfrom off to on position in Well known manner. Since the switch unit illustrated is conventional so far as its operative mechanism is concerned, further descrip tion of such mechanism is not necessary here. What is important is the manner in which the unit nts into the casing and makes easily separable electrical connection with the power connection assembly.

As illustrated, each of the stationary electrical contacts 23 is formed with an externally funnelshaped, preferably solid, conductive foot 26 projecting outwardly therefrom as a male plug-in terminal for close mechanical and electrical engagement with a corresponding one of the internally funnel-shaped grommets Il of the power connection assembly. A spider plate 21, secured to the body of the switch unit by means of the screws 28, Fig. 2, is adapted to be secured to the inturned ears II of the box body Illa by means of screws 29, see especially Figs. 3 and 4, whereby the switch unit 22 as a whole is removably fastened within the box body.

As shown in Fig. 4, the switch unit may be quickly and easily removed for inspection or repair by merely unscrewing the screws 29 and pulling the entire unit outwardly of the mouth I2 of the box. It may be as quickly and easily replaced by merely pushing it into position within the box body, the plugin feet 26 sliding into tight engagement with their respectively corresponding socket terminals Il, see Fig. 3. The upper surface of the top insulating plate I6 may be recessed slightly, as shown at 30, to accommodate projecting parts of the switch unit.

The removable cover IIlb of the switch box fits snugly over the upstanding neck portion Ic of the box body, and is secured in place by screws 3|, Fig. 1, which thread into receiving openings 32, Fig. 2, of spider plate 2l and are easily unscrewed when it is desired to remove the switch unit 22 from the box, as hereinbefore described.

The switch lever 25 extends through suitably provided apertures in both the spider plate 21 and cover IU, so as to be available outside the box for f -1 manually actuating the switch from off to on" positions and vice versa.

The above embodiments well exemplify the generic aspects o the invention, and are clearly indicative of how those skilled in the art can apply the principles of the invention to other similar connection devices, such as receptacles or convenience outlets. In the latter instance the switch unit would be replaced by a socket or plug-in type of connection unit, the framework and actual power connection elements being arranged to suit the particular connection unit employed, it being kept in mind that the base supporting the power connection, and the connection unit separably mated therewith, are the prime elements concerned.

Whereas this invention is here illustrated and described with respect to certain preferred forms thereof, it should be understood that the inventive concepts dened by the following claims may be embodied in other forms 'by those skilled in the art without departing from the generic teaching or scope of the invention.

I claim:

An electric switch box, comprising a separable casing having a shallow cover part and a relatively deep body part; an electric power connection assembly secured within said body part oi the casing substantially at the bottom thereof, said assembly comprising an insulating base plate, an insulating top plate, and spaced, oppositely disposed sets of spaced electrical terminal strips sandwiched between the said base and top plates at opposite ends thereof, means for electrically connecting the outer ends of said terminal strips at one end of the said assembly to respective electric power supply conductors, means for electrically connecting the outer ends of said terminal strips at the opposite end of said as sembly to respective electric power delivery conductors, electrical terminal contacts at the re- 5 spective inner ends of all of said terminal strips and exposed for interconnection with corresponding electrical contacts of a removable switch unit; said electrical terminal contacts comprising funnel-shaped grommets which extend through the said top plate and secure the respective electrical terminal strips thereto; an electric switch unit adapted to be removably disposed within said casing, and having a set of electrical terminal contacts exposed for interconnection with the said terminal contacts of the power connection assembly, said terminal contacts of the s-Witch unit comprising plug-in mem- -bers which mate with said terminal contacts of the power connection assembly-:when the switch unit is in place within said casing.

ISIDORE KORN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 10 Number Name Date 1,938,309 Williams Dec. 5, 1933 2,351,632 OBrien June 20, 1944 2,397,688 Osinski Apr. 2, 1946 

